In the early 2000s, actress Bethany Joy Lenz was enjoying life as one of the stars of One Tree Hill, the popular teen drama that also starred Sophia Bush, Chad Michael Murray, and Hilarie Burton.

But throughout filming, she tells PEOPLE, she led a double life: At the same time, she was also deeply devoted to a small, ultra-Christian group led by a shady pastor in Idaho, who controlled her career, life choices and, eventually, her bank account.

By the time she got out a decade later, she had to start over with hardly anything to show for the nearly nine years she spent on the series — and a feeling of regret and shame for not realizing she was in a cult.

In her memoir Dinner for Vampires Life on a Cult TV Show (While also in an Actual Cult!) (out Oct. 22), Lenz tells the whole story for the first time.